Appeal No. 95-4159
Application 08/151,055
collective teachings of Fay and Laska would have suggested the
invention as recited in claim 1.
Appellant argues that there is no motivation to
combine the teachings of Fay with Laska [brief, pages 6-7].
According to appellant, the IGBTs of Fay and Laska operate so
differently that the artisan would not selectively pick and
choose elements from the two devices to arrive at the claimed
invention. The examiner responds that appellant’s arguments
are not commensurate in scope with the invention of claim 1.
Although the examiner is correct to note that
arguments of nonobviousness must be commensurate in scope with
the claimed invention, the examiner must still consider the
propriety of combining prior art teachings based on what would
have been suggested to the artisan who has this prior art
before him. The Fay IGBT has a buffer layer which makes it a
punch-through (PT) type device. Laska discloses a non-punch-
through (NPT) IGBT which is designed to have operating
characteristics similar to a PT IGBT. While PT IGBTs and NPT
IGBTs operate to achieve similar results, they achieve these
results in an entirely different manner. Laska notes that an
NPT IGBT is fabricated using no life-time-killing steps
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